1. Field of the Invention
The methods of the invention are directed generally to the field of anatomical pathology, more specifically to the art of tissue staining. Yet more particularly, the methods demonstrate a novel technique for enhancing workflow through the AP lab by better coordination of information management.
2. Description of Related Art
Traditional manufacturing processes often encompass single skilled operators, high work in process inventories, constant expediting, and production schedule shuffling. These features add limiting effects, such as inefficiency in output, manpower, high work in progress inventories, and assembly line operations. Originally, lean production was implemented in manufacturing or assembly line processes to overcome the problems associated with traditional manufacturing. Lean production was based on the Toyota manufacturing system and typical practices can be found in “The Machine that Changed the World,” by James P. Womack, 1991, Harper Collins Publishing Co. The basic philosophy of the lean production system is to manufacture in the most economical way possible. This is accomplished by focusing on meeting customer requirements, such as producing a high-quality product while minimizing wasted resources and time.
The hospital-based Anatomical Pathology (“AP”) laboratory has evolved around the individual patient case. That is, each patient will require anywhere from 1 to approximately 20 tests (slides), based on the clinician's initial diagnosis. Therefore, AP labs have evolved a series of “batch”-based processes that reflect this initial workflow model. To accommodate the AP labs, companies have provided workflow solutions that emulate this batch process, and the AP lab has evolved into a series of batch workflow modules. Traditionally, IHC and Special Stains tissue staining was performed manually, and up to about 1991 with the advent of the 320 System from Ventana Medical Systems, Tucson, Ariz., there was no alternative to the tedious manual staining process. The tissue staining process is divided into a series of fundamental steps comprising embedding the tissue in paraffin, sectioning the tissue into thin (4 microns is typical) slices called “sections,” mounting the sections on a microscope slide, deparaffinizing the paraffin-embedded tissue sections, changing the hydrophobic environment the tissue then exists in to an aqueous environment via a series of graded xylene/alcohol/water baths, staining the tissue using one of five basic techniques (H&E, Papanicolau stain, IHC, ISH or Special Stains), re-grading the tissue to a hydrophobic environment, and finally coverslipping the tissue for archival purposes. Most of these processes are performed on a “batch” of samples simultaneously for economy of scale. Automated tissue staining can be thought of as a series of automated batch processes that mimics, for the most part, the manual processes.
For example, one of the first steps is embedding the tissue in paraffin so that it can later be manually cut by a microtome into a section. Companies such as Sakura (TISSUE-TEK™), ThermoShandon (EXCELSIOR™), Leica (ASP300™), and Vision Biosytems (PELORIS™) and others provide tissue processors that process tissue blocks by the hundreds, but all in batch mode. There is one new entrant that purports to continuously process tissue, the Sakura Xpress™. Also, most Hematoxylin & Eosin primary staining systems are also batch in that they stain baskets or trays of slides in large numbers simultaneously. See, e.g., the Leica XL Stainer, the Sakura DRS-60, etc.
A fundamental concern in today's AP lab is sample tracking. Hospitals are continuously challenged by the size and complexity of testing requirements, as clinicians and primary care professionals demand more and faster turnaround times. Opposed to this pressure for more/better/faster is the need to unambiguously track samples so that mix-ups and errors do not occur. The computer is ideally situated to do this, and so hospital information systems have been developed to track every hospital-based activity from admissions to testing. In addition, systems vendors have also designed Laboratory Information Systems (“LIS”) that are a part of or integrate with the Hospital Information System (“HIS”) so that labs can manage their unique requirements while remaining in contact with their customers. A typical LIS is designed and sold by Cerner as the PathNet® family of laboratory information solutions (Cerner Corp., Kansas City, Kans.).
A typical workflow in today's AP lab is shown in FIG. 1. It is a mix of manual and automated batch processes that is ripe for additional improvement. A fundamental issue remaining to be resolved is the lack of a complete information tracking solution for the entire tissue staining process.